c# - 模糊半透明形式的背景(如 Aero 玻璃)

Question

我有一个无边框、不可调整大小的 WPF 窗体(WindowStyle=None、AllowsTransparency=True、ResizeMode=NoResize)，背景是半透明的。下面是在记事本上运行的半透明红色矩形窗体的图片:

但是，我希望背景变得模糊，就像 Aero glass 那样，除了没有所有花哨的窗口边框和带条纹的彩色背景 - 我想自己处理。这是我希望它看起来像的模型:

我怎样才能以最有效的方式实现这一目标？

WinForms 或 WPF 对我来说没问题。希望它应该使用与 Aero glass 相同的东西(我对它只在启用 Aero 的情况下工作很好)，而不是像将下面的屏幕区域捕获为位图并对其进行模糊处理这样疯狂的事情。

这是我不想要的图片:

我知道这是可能的，我知道怎么做，但我不希望整个 Aero 玻璃窗口镶边、边框和标题栏或窗口具有用户设置的 Aero 玻璃颜色，只是模糊窗口/表单下方的任何内容的效果。

Answer 1

如果你想使用 Aero 模糊，那么你可以使用 DwmEnableBlurBehindWindow 接口(interface)。下面是一个利用它的示例派生窗口。

public class BlurWindow : Window
{
    #region Constants

    private const int WM_DWMCOMPOSITIONCHANGED = 0x031E;
    private const int DWM_BB_ENABLE = 0x1; 

    #endregion //Constants

    #region Structures
    [StructLayout( LayoutKind.Sequential )]
    private struct DWM_BLURBEHIND
    {
        public int dwFlags;
        public bool fEnable;
        public IntPtr hRgnBlur;
        public bool fTransitionOnMaximized;
    }

    [StructLayout( LayoutKind.Sequential )]
    private struct MARGINS
    {
        public int cxLeftWidth;
        public int cxRightWidth;
        public int cyTopHeight;
        public int cyBottomHeight;
    } 
    #endregion //Structures

    #region APIs

    [DllImport( "dwmapi.dll", PreserveSig = false )]
    private static extern void DwmEnableBlurBehindWindow(IntPtr hwnd, ref DWM_BLURBEHIND blurBehind);

    [DllImport( "dwmapi.dll" )]
    private static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMargins);

    [DllImport( "dwmapi.dll", PreserveSig = false )]
    private static extern bool DwmIsCompositionEnabled(); 

    #endregion //APIs

    #region Constructor
    public BlurWindow()
    {
        this.WindowStyle = System.Windows.WindowStyle.None;
        this.ResizeMode = System.Windows.ResizeMode.NoResize;
        this.Background = Brushes.Transparent;
    } 
    #endregion //Constructor

    #region Base class overrides
    protected override void OnSourceInitialized(EventArgs e)
    {
        base.OnSourceInitialized( e );

        if ( Environment.OSVersion.Version.Major >= 6 )
        {
            var hwnd = new WindowInteropHelper( this ).Handle;
            var hs = HwndSource.FromHwnd( hwnd );
            hs.CompositionTarget.BackgroundColor = Colors.Transparent;

            hs.AddHook( new HwndSourceHook( this.WndProc ) );
            this.InitializeGlass( hwnd );
        }
    } 
    #endregion //Base class overrides

    #region Methods

    #region InitializeGlass
    private void InitializeGlass(IntPtr hwnd)
    {
        if ( !DwmIsCompositionEnabled() )
            return;

        // fill the background with glass
        var margins = new MARGINS();
        margins.cxLeftWidth = margins.cxRightWidth = margins.cyBottomHeight = margins.cyTopHeight = -1;
        DwmExtendFrameIntoClientArea( hwnd, ref margins );

        // initialize blur for the window
        DWM_BLURBEHIND bbh = new DWM_BLURBEHIND();
        bbh.fEnable = true;
        bbh.dwFlags = DWM_BB_ENABLE;
        DwmEnableBlurBehindWindow( hwnd, ref bbh );
    }
    #endregion //InitializeGlass

    #region WndProc
    private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
        if ( msg == WM_DWMCOMPOSITIONCHANGED )
        {
            this.InitializeGlass( hwnd );
            handled = false;
        }

        return IntPtr.Zero;
    } 
    #endregion //WndProc 

    #endregion //Methods
}

这里是使用 BlurWindow 的片段。

var w = new BlurWindow();
w.Width = 100;
w.Height = 100;
w.MouseLeftButtonDown += (s1, e1) => {
    ((Window)s1).DragMove();
    e1.Handled = true;
};
w.Background = new SolidColorBrush( Color.FromArgb( 75, 255, 0, 0 ) );
w.Show();